KR-102962750-B1 - ENHANCED COVERSION OF CARBON DIOXIDE IN MICROBIAL ELECTROSYNTHESIS SYSTEM WITH CARBON BASED MEMBRANE ELECTRODE, AND METHOD OF THE SAME

Abstract

The present disclosure provides a microbial electro-biosynthesis system using a carbon-based membrane electrode and a method thereof for improving the conversion efficiency of carbon dioxide. The microbial electro-biosynthesis system of the present disclosure comprises an oxidation chamber having an oxidation electrode, a reduction chamber having a reduction electrode, and a cation exchange membrane separating the oxidation chamber and the reduction chamber, wherein the reduction electrode may be implemented as a hollow fiber type water-permeable electrode made of a carbon-based material. Furthermore, the microbial electro-biosynthesis system of the present disclosure may inject an electrolyte in which carbon dioxide is dissolved into the reduction chamber and obtain methane converted from carbon dioxide using the reduction electrode.

Inventors

• 강석태
• 한승엽
• 박주성
• 이미영

Assignees

• 한국과학기술원

Dates

Publication Date

20260508

Application Date

20221005

Claims (10)

1. In microbial electro-biosynthetic systems, An oxidation chamber having an oxidation electrode and configured to generate hydrogen ions from incoming water through the oxidation electrode; A reduction chamber having a reduction electrode implemented as a hollow fiber water-permeable electrode made of a carbon-based material, into which an electrolyte containing dissolved carbon dioxide is injected, and configured to convert the carbon dioxide into methane using hydrogen ions through the reduction electrode; A cation exchange membrane configured to separate the oxidation chamber and the reduction chamber and to transfer hydrogen ions from the oxidation chamber to the reduction chamber; and A pump configured to deliver the electrolyte in which the carbon dioxide is dissolved, located within the reduction chamber, into the interior of the reduction electrode through the hollow of the reduction electrode. including, Microbial electro-biosynthetic system.
2. In Article 1, Electrochemically active microorganisms are attached to the surface of the above reduction electrode, Microbial electro-biosynthetic system.
3. In Article 2, The above electrolyte in which the carbon dioxide is dissolved is, It is transferred from the outside of the reduction electrode to the surface of the reduction electrode through diffusion within the reduction chamber, and It is delivered to the hollow of the reduction electrode by convection through the pump and permeates from the interior of the reduction electrode to the surface of the reduction electrode, and The above carbon dioxide is, Converted into methane through the above electrochemically active microorganisms, Microbial electro-biosynthetic system.
4. In Article 1, The above carbon-based material is, A carbon nanotube structure comprising carbon nanomaterials, Microbial electro-biosynthetic system.
5. In a method performed in a microbial electro-biosynthetic system, The above microbial electro-biosynthetic system is, An oxidation chamber having an oxidation electrode and configured to generate hydrogen ions from incoming water through the oxidation electrode; A reduction chamber having a reduction electrode implemented as a hollow fiber water-permeable electrode made of a carbon-based material; A cation exchange membrane configured to separate the oxidation chamber and the reduction chamber and to transfer hydrogen ions from the oxidation chamber to the reduction chamber; and A pump connected to the above reduction electrode Includes, The method performed in the above-described microbial electro-biosynthetic system is, A step of injecting an electrolyte in which carbon dioxide is dissolved into the above reduction chamber; A step of transferring the electrolyte in which the carbon dioxide is dissolved in the reduction chamber to the interior of the reduction electrode through the hollow of the reduction electrode using the above pump; and A step of converting carbon dioxide into methane using hydrogen ions through the reduction electrode to obtain methane. including, A method performed in a microbial electrobiosynthetic system.
6. In Article 5, Electrochemically active microorganisms are attached to the surface of the above reduction electrode, A method performed in a microbial electrobiosynthetic system.
7. In Article 6, The above electrolyte in which the carbon dioxide is dissolved is, It is transferred from the outside of the reduction electrode to the surface of the reduction electrode through diffusion within the reduction chamber, and It is delivered to the hollow of the reduction electrode by convection through the pump and permeates from the interior of the reduction electrode to the surface of the reduction electrode, and The above carbon dioxide is, Converted into methane through the above electrochemically active microorganisms, A method performed in a microbial electrobiosynthetic system.
8. In Article 5, The above carbon-based material is, A carbon nanotube structure comprising carbon nanomaterials, A method performed in a microbial electrobiosynthetic system.
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Description

Microbial Electrosynthesization System with Carbon-based Membrane Electrode for Enhanced Conversion Efficiency of Carbon Dioxide and Method thereof The present disclosure relates to a microbial electrobiosynthetic system using a carbon-based membrane electrode for improving the conversion efficiency of carbon dioxide and a method thereof. Carbon dioxide generated in industry has been identified as a major culprit in increasing global warming, leading to active research on converting it into useful resources through various technologies. Among these, electrochemical carbon dioxide conversion systems utilizing microorganisms, when combined with microbial fuel cells, can convert carbon dioxide into useful organic substances (e.g., methane, acetic acid) using self-generated energy through electrochemically active microorganisms attached to the reduction electrode, in addition to decomposing organic waste. However, the conversion efficiency is significantly slow because carbon dioxide moves to the electrochemically active microorganisms based on diffusion rates. Furthermore, there is a problem in that the gas or solution within the reaction vessel must be collected after a certain period and subjected to an additional separation process to recover the organic substances generated by the carbon dioxide reduction reaction. FIG. 1 is a drawing illustrating a microbial electro-biosynthetic system according to the present disclosure. FIG. 2 is a diagram illustrating the performance of a microbial electro-biosynthetic system according to the present disclosure. FIG. 3 is a drawing illustrating a carbon nanotube structure used as a reduction electrode according to the present disclosure and a method for manufacturing the same. FIG. 4 is a table for explaining the characteristics of a water-permeable electrode of a carbon-based material as a reduction electrode of the present disclosure. Figure 5 is a diagram and graph illustrating the electrochemical performance of electroactive microorganisms attached to the surface of a reduction electrode of a carbon-based material according to the present disclosure. FIG. 6 is a graph showing the carbon dioxide methane production rate, current density, and Coulomb efficiency of the microbial electrobiosynthetic system of the present disclosure. The present disclosure proposes a technology for manufacturing a water-permeable electrode, such as a hollow fiber type, flat film type, or cylindrical type, using a conductive carbon-based material (e.g., carbon nanotubes, graphene, etc.), and using it as a reduction electrode in a microbial electro-biosynthesis system. According to the present disclosure, in a microbial electro-biosynthesis system, the methane conversion rate of carbon dioxide and Coulomb efficiency can be improved by allowing the water-permeable electrode to directly flow through an electrolyte in which carbon dioxide is dissolved into the electrode. Hereinafter, various embodiments of the present disclosure are described with reference to the accompanying drawings. FIG. 1 is a drawing illustrating a microbial electro-biosynthetic system (100) according to the present disclosure. Referring to FIG. 1, a microbial electro-biosynthetic system (100) continuously treats influent water under anaerobic conditions and may include an oxidation chamber (110), a reduction chamber (120), a cation exchange membrane (130) separating the oxidation chamber (110) and the reduction chamber (120), and a pump (140) coupled to the reduction chamber (120). The oxidation chamber (110) may be configured to induce a water splitting reaction with respect to the incoming water. To this end, the oxidation chamber (110) may include an oxidation electrode (111). The oxidation electrode (111) can generate hydrogen ions through a water splitting reaction within the oxidation chamber (110). For example, as the oxidation electrode (111), a metal electrode such as Ti or Pt, which generates a large amount of hydrogen ions through the water splitting reaction, or a carbon electrode such as carbon fiber or carbon cloth may be used. The reduction chamber (120) may be configured to induce a carbon dioxide reduction reaction together with hydrogen ions from the oxidation chamber (110). To this end, the reduction chamber (120) may include a reference electrode (121) and a reduction electrode (123). The reference electrode (121) may be configured to apply a voltage within the reduction chamber (120). For example, a silver-silver chloride electrode (Ag/AgCl) may be used as the reference electrode (121), and other electrodes such as a calomel electrode or a mercury sulfate electrode may also be used. The reduction electrode (120) may be configured to induce a carbon dioxide reduction reaction together with hydrogen ions from the oxidation chamber (110) based on the voltage applied by the reference electrode (121). The reduction electrode (123) may be implemented as a water-permeable electrode of a conductive carbon-